Fire Brick angle on first layer when forming Dome

[Riverogue]

Hi Folks,
Obviously, depending on the height and diameter of the dome, one's angle will vary when starting the oven. My drawings dictate to me a seven degree rise off 180 on the first layer. The inside diameter of the oven is 42 inches. The inside of the domes height is 22.25 inches. Can anyone give me some feedback relating to this. It would be appreciated.
Thanks
The Rogue

[deejayoh]

Re: Fire Brick angle on first layer when forming Dome

Think it would be easier to answer your question if you posted a copy of your drawings. I'm sure there is some mathematical way to do this, but I based mine all on sketchup drawings too.

[OzOvenBuilder]

Re: Fire Brick angle on first layer when forming Dome

Have you used or have access to AutoCAD? It's quite easy to do a simple sketch with the measurements you have and then measure the angles within the program!

[Les]

Re: Fire Brick angle on first layer when forming Dome

I used 12 courses to get to the top (21 inches). 90 degrees divided by 12 is 7.5 deg / course.

EDIT The plug was cut at an angle as well so if you count 13 courses, thats pretty close to your 7 deg.

[Riverogue]

Re: Fire Brick angle on first layer when forming Dome

Hi Folks
Am presently using the auto cad software 2002. Very effective and helpful. Just wanted to confirm for myself that I'm on the right track. Many thanks to Ozovenbuilder,Deejayoh,Les and Boom Shanker for your input.
The Rogue